Kumar M, Ahmad T, Sharma A, Mabalirajan U, Kulshreshtha A, Agrawal A, Ghosh B. Let-7 microRNA-mediated regulation of IL-13 and allergic airway inflammation.
J Allergy Clin Immunol 2011;
128:1077-85.e1-10. [PMID:
21616524 DOI:
10.1016/j.jaci.2011.04.034]
[Citation(s) in RCA: 240] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 04/12/2011] [Accepted: 04/13/2011] [Indexed: 12/16/2022]
Abstract
BACKGROUND
IL-13, a cytokine secreted by T(H)2 lymphocytes and other cells, critically modulates allergic inflammation and tissue remodeling in allergic asthma. Although much is known about transcriptional regulation of IL-13, posttranscriptional regulation is poorly understood.
OBJECTIVE
Because many inflammatory pathways are known to be regulated by microRNAs, permitting a rapid and fine-tuned response, the role of microRNA-mediated regulation of IL-13 was investigated using both in vitro and in vivo studies.
METHODS
A combination of in silico approaches and in vitro transfections in A549 cells and primary cultured T cells was used to demonstrate the involvement of let-7 in IL-13 regulation. Furthermore, intranasal delivery of let-7 microRNA mimic in mice was performed to study its effects in allergic airway inflammatory conditions.
RESULTS
Using a combination of bioinformatics and molecular approaches, we demonstrate that the let-7 family of microRNAs regulates IL-13 expression. Induced levels of IL-13 in cultured T cells were inversely related to let-7 levels. In an IL-13-dependent murine model of allergic airway inflammation, we observed that inflammation was associated with a reduction in most of the members of the let-7 family. Exogenous administration of let-7 mimic to lungs of mice with allergic inflammation resulted in a decrease in IL-13 levels, resolution of airway inflammation, reduction in airway hyperresponsiveness, and attenuation of mucus metaplasia and subepithelial fibrosis.
CONCLUSION
Let-7 microRNAs inhibit IL-13 expression and represent a major regulatory mechanism for modulating IL-13 secretion in IL-13-producing cell types and thereby T(H)2 inflammation.
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